In recent years, electroluminescent devices with high luminous efficiency using electroluminescent devices such as light emitting diodes (LEDs) and organic ELs have attracted attention. An electroluminescent device includes an emissive layer sandwiched between planar-type cathode and anode (emissive layer), typically configured with a transparent electrode as the anode and a metal reflective electrode as the cathode in many cases. Applications of electroluminescent devices include cases of lighting that needs luminance with a specific angular range with a specific color, such as downlights for decorative illumination, colored spotlights in theaters, colored signaling flashlights, traffic signals, colored front lights, backlights, brake lights for cars.
In typical cases, however, angular distribution (light distribution) of the light intensity in the electroluminescent device using the electroluminescent device is Lambertian light distribution represented by cos θ, having difficulty in achieving a light source capable of emitting light with high intensity in a specific angular range.
Meanwhile, there are proposed techniques disclosed as a background art including a technique of arranging an optical multilayer film near a light emitting functional layer to adjust light distribution and emission color as disclosed in JP 2015-038859 A (Patent Literature 1) and JP 2013-157226 A (Patent Literature 2), and a technique of arranging an optical filter outside the device to correct a color shift of reflected light as disclosed in JP 2014-048610 A (Patent Literature 3).